VIncristine, irinotecan, and temozolomide in children and adolescents with relapsed rhabdomyosarcoma.

Background: The combination of vincristine, irinotecan, and temozolomide (VIT) is often used to treat children and adolescents with relapsed rhabdomyosarcoma (RMS); however, the outcome of these patients has not been previously described.

Procedures: We sought to determine the response rate (RR) and progression-free survival (PFS) for patients with relapsed RMS treated with VIT by retrospective review of patients treated at five tertiary care hospitals. Prior treatment with irinotecan was permitted.

Results: Among 19 patients with a median age of 8 years (range 2-17 years), 12 (63%) were males and 12 (63%) had embryonal histology. Median time to relapse from initial diagnosis was 16 months (range 2.8-45 months). VIT was used as first, second, third, or fourth line of therapy in four (21%), seven (37%), six (32%), and two (10%) patients, respectively. Four patients received VIT as adjuvant therapy following radiation and/or surgery. Therefore, among 15 evaluable patients, the best response to VIT was 0 (complete response, CR), 0 (partial response, PR), 4 (stable disease, SD), and 11 (progressive disease, PD) for an overall clinical benefit rate (CR + PR + SD) of 26.7% (95% CI: 7.8-55.1%). After a median follow-up of 8 months, 2 (10%) patients were alive without disease, 3 (16%) were alive with disease, and 14 (74%) patients died of PD. PFS at 3 months was 23% (95% CI: 5.7-46.7%).

Conclusions: VIT therapy in combination with adequate local control is associated with some disease control in patients with first relapse RMS and may be another reasonable option to offer patients as salvage therapy.